LinkedIn Likes API (Post Reactions)

Automate LinkedIn post engagement through the WarmySender REST API. The LinkedIn Likes API lets you programmatically add reactions to posts using API key authentication — perfect for AI agents, CRM integrations, and automated outreach workflows.

Getting Started:

  1. Go to Settings > API Keys and create a new API key.
  2. Select the 'linkedin:read' and 'linkedin:write' scopes.
  3. Copy your API key (shown once — save it securely).
  4. Use the key in the Authorization header: Authorization: Bearer YOUR_API_KEY

Available Endpoints:

Post ID Format:
The postId is the LinkedIn post URN in the format 'urn:li:activity:1234567890'. When placing it in the URL path, URL-encode the colons: urn%3Ali%3Aactivity%3A1234567890

Account Safety & Rate Limits:
Daily engagement limits are enforced per LinkedIn account based on account age and strategy. This protects your LinkedIn account from being flagged:
• New accounts (< 6 months): Start at 5 engagements/day, ramp to 30 over 6 weeks
• Established accounts (6-12 months): Start at 15/day, ramp to 40 over 4 weeks
• Veteran accounts (1+ year): Start at 25/day, ramp to 50 over 2 weeks
• Recovery (after restriction): Start at 2/day, very slow 8-week ramp to 15/day
The API returns 429 with details when the daily limit is reached.

Use Cases:

1. AI Sales Agents — Build AI agents that engage with prospects' posts before sending connection requests. Liking a post signals interest and increases acceptance rates.

2. Pre-Outreach Warming — Like a prospect's recent post on Day 1, then send a cold email or connection request on Day 3. This multichannel touch builds familiarity.

3. CRM-Triggered Engagement — Connect your CRM to automatically like posts from high-value leads when they publish new content.

4. Content Monitoring — Use the GET reactions endpoint to monitor engagement on target posts and identify trending content for outreach timing.

5. Multi-Account Rotation — If you have multiple LinkedIn seats, distribute likes across accounts to maximize daily engagement capacity.

For full API documentation with code examples, visit the API Reference page at /docs/integrations.

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